In certain circumstances, a person may wish other parties to have access to personal information which he/she would normally wish to remain private. For example, a guest at a hotel may wish the hotel to have access to details such as name and address of next of kin, serious medical conditions, etc in the event of an accident occurring during their stay at the hotel. However, the person may not be comfortable with having hotel staff reading their personal information other than in an emergency situation. To overcome this problem, it is known to write personal information on a piece of paper which is then sealed inside an envelope. The guest then presents the sealed envelope and contents to the hotel reception upon arrival, instructing them that it contains information which may be necessary in an emergency. In the event of an emergency the hotel staff would then be able to open the envelope to find out the information contained in it. If no emergency situation arose during the guest's stay, the guest would retrieve the sealed envelope at the end of their stay, reassured in the knowledge that the contents of the envelope have not been disclosed if the envelope's seal is intact.
The owner of the envelope must rely upon their own assessment of whether the envelope has been opened or not. If another party was determined to discover the contents of the envelope, they might try to deceive the owner by resealing the envelope after opening it, or replacing an opened envelope with an identical new one.
The known paper sealed envelope is only available to the party which the owner has given it to. In some instances, it might not be possible to retrieve the envelope from the party to whom it was given, for example if an accident occurred, medical staff arriving at the scene may be unaware of the existence of the sealed envelope at the hotel. A possible solution to this problem would be for the person to carry the sealed envelope at all times. However, this would mean that sensitive information would be vulnerable if the envelope was lost or stolen. It would also be desirable for the information to be available for more than one party, for example a chain of hotels which the guest regularly stays in, or a hotel would also be able to give a copy of the sealed envelope to local hospitals in case of an emergency. However, the envelope owner would need to keep track of all the envelopes to ensure that none of the contents had been read.
People often carry information in electronic form, for example in devices such as personal organizers or a mobile phone's memory. Information stored in electronic form has advantages for the user, such as being able to search for certain information quickly. However, unless the information is protected by some means the information may be read by anybody who has access to the electronic device with or without the owner's consent. Additionally, the owner of the device may not be aware of unauthorized access since most electronic personal organizer devices do not keep a record of data accesses. In an attempt to prevent unauthorized access many electronic databases are protected by a password. The problem with using passwords is that they must be provided to everybody who might need to access the information stored in electronic form in an emergency.